make Plugin an abstract class to improve binary compatibility
make Plugin an abstract class to improve binary compatibility

shiena/gitbucket,xuwei-k/gitbucket,x-way/gitbucket,nus/gitbucket,gencer/gitbucket,xuwei-k/gitbucket,McFoggy/gitbucket,xuwei-k/gitbucket,gitbucket/gitbucket,shiena/gitbucket,McFoggy/gitbucket,kounoike/gitbucket,zhoffice/gitbucket,nobusugi246/gitbucket,rabitarochan/gitbucket,nobusugi246/gitbucket,kounoike/gitbucket,rabitarochan/gitbucket,nobusugi246/gitbucket,McFoggy/gitbucket,gencer/gitbucket,gitbucket/gitbucket,gencer/gitbucket,gencer/gitbucket,x-way/gitbucket,mann-ed/gitbucket,rabitarochan/gitbucket,mrkm4ntr/gitbucket,zhoffice/gitbucket,mrkm4ntr/gitbucket,kounoike/gitbucket,x-way/gitbucket,gitbucket/gitbucket,kounoike/gitbucket,s-takatsu/gitbucket,imeszaros/gitbucket,zhoffice/gitbucket,superhj1987/gitbucket,nus/gitbucket,mann-ed/gitbucket,xuwei-k/gitbucket,nus/gitbucket,imeszaros/gitbucket,nus/gitbucket,rabitarochan/gitbucket,s-takatsu/gitbucket,zhoffice/gitbucket,s-takatsu/gitbucket,gitbucket/gitbucket,takezoe/gitbucket,mann-ed/gitbucket,shiena/gitbucket,nobusugi246/gitbucket,takezoe/gitbucket,superhj1987/gitbucket,takezoe/gitbucket,takezoe/gitbucket,x-way/gitbucket,superhj1987/gitbucket,McFoggy/gitbucket,shiena/gitbucket,imeszaros/gitbucket,mrkm4ntr/gitbucket,superhj1987/gitbucket,mann-ed/gitbucket,imeszaros/gitbucket,mrkm4ntr/gitbucket,s-takatsu/gitbucket